This invention relates to borescopes/endoscopes having an elongated insertion tube with a video pickup device at the distal end thereof. More particularly, this invention relates to a borescope/endoscope having means for measuring the various parameters of an object being viewed on a video pickup display screen.
For many years now, borescopes/endoscopes of the type having an elongated insertion tube with a video pickup at the distal end for viewing remotely located targets have been common devices in the art. More recently, means for measuring dimensions and other parameters of the object being viewed have been proposed which permit measurements without the necessity of providing a scale or a known spacing of the end of the video probe from the object being viewed. Typical of this type of device are co-pending applications assigned to the common assignee of the present case entitled System for Measuring Objects Viewed Through a Borescope, Ser. No. 364, filed June 12, 1989 now U.S. Pat. No. 4,980,763, issued Dec. 25, 1990 and Video Measurement With Automatic Distortion and Calibration , Ser No 506,175 filed Apr. 9, 1990 (050).
According to these applications, in order to measure an object, an image or shadow having a known characteristic is projected onto the object being viewed. Variations in the known characteristics of the shadow are used to calibrate the measurement of the dimensions of the object being viewed. In certain applications where it is desired to measure the characteristics of the object being viewed, it is also desirable to view the object without the interference of a shadow or other auxiliary characteristic being projected onto the object being viewed.